4 LNBs to twin tuner receiver

Frisbee78

Hi all,

New to this forum to get your thoughts on my planned setup as it has been 15 years since I last played with satellite equipment.

Anyways, here’s the plan: I would like to receive the FTA/FTV channels in English, French and Dutch from the satellites at 28.2°, 19.2° and 23.5°E. I would also like to view and record programs simultaneously from any of these satellites (i.e. watch a program from 28.2 and record something on 19.2). I’d want the recording to be digital lossless and if the receiver was HD capable, all the better.

Since I live in Scotland and would like the most reliable signal possible without filling for a planning application, I am considering a 90cm dish with 3, or 4 twin or quad LNBs (could set the 4th one on 13°E). The Triax TD 88 seems to come with decent brackets to which mount some 0.2dB Titanium LNBs. I was then planning on feeding two of the LNBs’ outputs into a pair of DISEQC 4-in-1 to mix the 4 LNBs into the two tuners of the receiver. Check this diagram to see what I’m on about: _http://repository.sepiro.com/sat.jpg
However, an article at the bottom of this page claims that this setup would not work: _http://www.satellitesuperstore.com/multisat.htm. Can anybody confirm this claim? I don’t really fancy dishing out £300 for a 17-in-6-out multiswitch where a couple of DISEQC 4-in-1 will do.

As for the receiver, since I’d need to decrypt FTV channels from Sky, the choice is limited as a Sky+ box can’t deal with the DISEQC and no, there’s no way I’d pay Sky £10 a month just to use their box as a recording device anyway. So with the need for dual tuner, DISEQC, CAM, HD support, and PVR functionality, looks like I need a Dreambox 8000… Great…

olisun

have a look at the Vantage 8000

Robbo71

Hi,

Regarding the DiSEqC switching arrangement. I have two twin LNBs ( a Smart Titanium and an Inverto Silvertech), both connected to a 4-way DiSEQc switch and they work fine, on either LNB output, so I wouldn't exactly disregard the advice given on that site, but ... the chances are that you won't have a problem. Since a DisEqC switch can cost just 4 quid, it is worth taking the slight risk that it won't work.

LNB wise you are going to need a couple of narrow feedhorn ones to deal with 23.5E and 19E as a normal LNB won't let them get close enough.

Topfield are also selling a twin tunered PVR HD model, not sure if it compatible with a Sky card, but has two CI slots for a suitable CAM.

Does the Vantage read a Sky card Oilsun?

Robbo

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jphili

Hi,

I'm using this configuration on 13, 19.2 and 28.2 for the moment without any issues.
Only issue that I once came across was using a monoblock for 13x19.2. That does always need to be connected on the A and B inputs of the switch, but with 4 separate LNBs there is no issue.
If you get quad LNBs instead of twins, do make sure to stay away from the Quatro LNBs, those need to be used with a totally different type of switch.

With regards as to receivers, I'm using a TopField 7700 PVR for the moment, which has what you need, except that I do not know how well it behaves with Sky and that you'll probably be limited for quite some time to the Now&Next EPG. The Dreambox is more open and thus could have more functionality coming sooner than the TopField. That is if you can afford the price of it and if you're not wary to work a little with Linux (that's running on the Dreambox).

Frisbee78

Thank you for your feedback guys.

Robbo, are you sure I need narrow feedhorns for 23.5 and 19.2 when fitted to a TD88? If so, then I guess the same applies to 28.2 which is only 0.5 deg further appart than 23.5 and 19.2 are. In that case, I guess the only option would be Alp quad LNBs.

I was planning on centering the dish on 19.2 since it's pretty much in the middle on my spectrum. Does that sound OK?

As for the inclinaison angle, do you just set it roughly?


Regarding the receiver, I haven't yet decided what to go for. I'll be taking that topic to the receiver channel of the forum.

Thanks everyone.

Robbo71

No, I'm not sure, I was guessing that it wouldn't fit due to the closeness, i.e just over 4 degrees. 3 degrees isn't possible. As for 28.2E and 23.5E, I was thinking that you might just get away with it, as 28E could be a little bit out and still work OK.

The narrow feedhorn LNBs would ensure that you did have room.

It is also possible to calculate the distance between the LNBs centres if you wanted to using some trig:

1. If you measure the distance between the LNB and the centre of the dish (call it d)

2. Say the azimuth between the two sats is 'theta'

3 Say the distance between the LNBs is 'x'

then x= d * Tan(theta)

I think on my TD110 I would just get 19.2 and 23.5,but it depends how wide the feedhorn is.


To set the dish up, you would position the dish using the signal from the central LNB, once that was spot on, you'd tackle the others. Remember the LNBs go on the opposite side, because the signal is reflected, also for lower elevations the LNB goes higher and vice versa.

When I set mine up ( I have no bracket, just using pieces of scrap), I calculated the positions first, then put them there, and then ducked down below the dish and adjusted for best signal.

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Robbo71

Out of interest, I just tried 13E, 19.2E and 23.5E on my TD110, seems to work OK, so it might on the TD88, but my 23.5E and 19.2E LNBs are touching. In the photo below, I have not done any adjustments either, it is just where it ended up when I taped it on.

The middle one is 19.2E, the RHS is 23.5E and the LHS is 13E (not quite right, it needs to come left a bit)

Attached Images

P7150326.JPG (35.2 KB, 10 views)

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Frisbee78

Wow Robbo, you're the man!

Thanks!

Robbo71

Best to use the proper bracket though, as adjustment is tricky using electrical tape.My dish is motorised anyway I just like playing.

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